1. Field of the Invention
This invention relates to excimer UV lamps.
2. Description of Related Art
Generally, it is known that excimers (excited dimers) are excited molecules with no stable ground state. They are formed via three body reactions involving excited-state atoms and ground state atoms. Excimers are normally unstable and decay in few nanoseconds, yielding incoherent radiation in the ultra-violet (UV) and vacuum ultra-violet (VUV) range. Excimers can be formed in high pressure, non-equilibrium, gas discharges such as the Dielectric Barrier Discharge (DBD).
Excimer formation typically occurs at high pressures where the collision rates are high. Therefore, a non-equilibrium, atmospheric pressure discharge provides an ideal source of excimers. In the market today, excimer UV lamps have generally a cylindrical configuration and are based on a silent discharge. This silent discharge is normally generated by applying an AC voltage to electrodes, which are insulated by a dielectric material. The applied AC voltage ionizes specific gases that are located between and within the vicinity of the electrodes and generate plasma discharges between the electrodes. The electrodes are powered by a RF source with voltages in the kilovolts range and frequencies in the kilohertz to megahertz range.
Excimer lamps typically emit ultra-violet (UV) radiation at specific wavelengths and known excimer lamps are usually used in industrial applications for decontamination or disinfection of materials, surface modifications of materials, material deposition, pollution control, and UV curing.